Abstract
Background : Mucoepidermoid carcinoma (MEC) of the lung is a rare pulmonary neoplasm and sometimes, when it manifests as a submucosal endobronchial tumor, preoperative cytological diagnosis could be difficult. Herein, we report a case of MEC arising from the lung that was difficult to diagnose by bronchial brushing and washing cytology.
Case : A 40-year-old woman visited our hospital with an abnormal opacity on the chest X-ray, that had been detected during a medical checkup. Chest CT revealed a well-defined nodule in the left lower bronchus. Bronchial brushing and washing cytology showed polygonal cells with centrally placed round nuclei, along with tiny foamy cells with cytoplasmic mucin and eccentrically placed nuclei, but no definitive diagnosis of malignancy could be made because of the mild atypia and low cellularity. Eventually, the tumor was diagnosed as a low-grade MEC of the lung by transbronchial biopsy and histopathological examination of the resected specimen.
Conclusion : Cytological diagnosis of low-grade MEC of the lung is sometimes difficult, particularly by bronchial brushing and washing cytology alone. However, the unique cytological characteristics taken into consideration with the clinical and radiological findings may allow a correct diagnosis of low-grade MEC to be made preoperatively.
